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Co-location of algae production facilities with cane sugar mills can be a technically advantageous path towards production of biodiesel. Algal biodiesel production was integrated with cane sugar production in the material and energy balance simulation program Sugars™. A model was developed that allowed comparison of production scenarios involving dewatering the algae to 20% ds (dry solids) or 30% ds prior to thermal drying. The net energy ratio, E(R) (energy produced/energy consumed) of the proposed process was found to be 1.5. A sensitivity analysis showed that this number ranged from 0.9 to 1.7 when the range of values for oil content, CO(2) utilization, oil conversion, and harvest density reported in the literature were evaluated. By utilizing available waste-resources from a 10,000 ton/d cane sugar mill, a 530 ha algae farm can produce 5.8 million L of biodiesel/yr and reduce CO(2) emissions of the mill by 15% without the need for fossil fuels.

Increased economic pressure in recent decades force sugar producers to consider valueadded technologies that can improve industry's sustainability. Carbon dioxide from boiler flue gas, water, and waste heat from sugar beet plants are resources that can be utilized for production of oil-containing algae. Algae production has been considered as a promising method of sequestration of carbon dioxide for conversion into jet and diesel fuels and chemicals. With oil content ranging between 30 and 50 % on dry mass, algae offer productivity10-20 times higher in comparison with oil producing land crops. Algal oil is easily converted into biodiesel via transesterification with ethanol, which can be obtained by fermentation of effluent streams from a sugar factory. Resulting biodiesel can be used to cover harvesting and transportation needs. Authors have previously analyzed the possibility of algal production in connection with raw cane mills. It was found that sugar cane mills can supply sufficient carbon dioxide from flue gas to support mass algae production, as well as provide sufficient electric power and steam required for conversion of algal biomass into biodiesel. In addition, cane mills generate significant amounts of clean water and have ponds available for algal production. Current presentation explores integration of algal technology into sugar beet processing facilities. Material and heat balances will be presented for operation scenarios where algae is produced adjacent to a 10,000 tpd sugar beet plant. Co-location of beet plants and algal production facilities will allow mitigation of greenhouse gases and offer benefits of utilization of existing agricultural infrastructure and resources while maintaining the same level of sugar production.

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